A son of a Webster Plantation couple whose bodies were found last Saturday, the victims of an apparent double homicide, was being held in the Penobscot County Jail on Friday for failing to appear in court, a jail spokesman said.

Matthew Miller, 26, of Lincoln, was charged on a warrant with failure to appear in Dover-Foxcroft District Court last month in connection with a charge of negotiating a worthless instrument, a Piscataquis County Sheriff’s Office spokesman said.

State police made the arrest on Thursday. The time of the arrest was not given, the sheriff’s spokesman said.

Miller was due to be transferred to the Piscataquis County Jail overnight Friday for an appearance Monday in Dover-Foxcroft District Court, the spokesmen said.

The bodies were found just before 1 p.m. when a visiting friend called 911 because no one answered the door. Teams of state police detectives have used a Maine Department of Transportation garage in Springfield as a gathering point for the investigation. Webster Plantation is a tiny rural community of about 70 people located between Springfield and Kingman in northern Penobscot County.

Michael Miller was found lying face up in his kitchen, with his legs folded behind him. Valerie was next to him with her head on his chest, family members have said.

Before the autopsies led to Monday’s double homicide ruling, investigators told family members that they suspected the two died of carbon monoxide poisoning, heart attacks or some other form of illness or sudden-onset affliction.

Since the ruling, state police have declined to comment on how the Millers died or whether an unidentified woman they seek, who might have been the last to see the Millers alive, is a suspect or person of interest.

Detectives would like anyone who traveled on Tucker Ridge Road between 9 a.m. and 2 p.m. last Saturday to call them at 800-432-7381 or 911 on a cell phone.

The unidentified woman is described as about 5 feet, 4 inches tall, 130 pounds, in her mid-50s, with bifocal glasses and graying dark hair tied in a ponytail.

Matthew Miller called the killings “very strange.” He said Tuesday that the family is willing to put up money for a reward, if necessary, to get information leading to arrests.

Stephen McCausland, spokesman for the Maine Department of Public Safety, said Friday that the investigation into the double homicide is continuing.